I only found this lovely game while looking for an open source "distributed system application" for a computer science class. Technically, I believe Wesnoth's multiplayer fits the bill, but I'm not sure where to look in the code to really understand how it all works. Which folders or files should I look at to understand how the multiplayer works?

Anyway, Wesnoth seems to be a pretty cool rpg, especially done by a community. I usually have an itch for tactics games. Any old fire emblem fans out there?

this wiki page https://wiki.wesnoth.org/OOS_(Out_of_Sync) tells you a little about how multiplayer works, although it's more focused on what could go wrong. Ther than that you can ofc look at the wesnoth source files on github.

Scenario with Robots SP scenario (1.11/1.12), allows you to build your units with components, PYR No preperation turn 1.12 mp-mod that allows you to select your units immideately after the game begins.